Carried out by researchers at the University of Manchester, the new study looked at 16 randomised controlled trials with a total of 45,826 participants to investigate the association between making dietary improvements and symptoms of depression and anxiety.
The findings, published in the journal Psychosomatic Medicine, showed that all types of dietary improvement, including those designed for weight loss, fat reduction or to increase nutrients, all appeared to have an equally beneficial effect on reducing the symptoms of depression, even in those without diagnosed depressive disorders.
Moreover, when dietary improvements were combined with exercise, the positive effect was even stronger.
However, the researchers could not determine a clear relationship between diet and anxiety, although they did find that female participants who improved their diet appeared to benefit from even greater improvements for symptoms of both depression and anxiety.
“The overall evidence for the effects of diet on mood and mental well-being had up to now yet to be assessed,” said study author Dr. Joseph Firth. “But our recent meta-analysis has done just that; showing that adopting a healthier diet can boost people’s mood. However, it has no clear effects on anxiety.”
“The similar effects from any type of dietary improvement suggests that highly-specific or specialised diets are unnecessary for the average individual,” continued Dr. Firth, “Instead, just making simple changes is equally beneficial for mental health. In particular, eating more nutrient-dense meals which are high in fiber and vegetables, while cutting back on fast-foods and refined sugars appears to be sufficient for avoiding the potentially negative psychological effects of a ‘junk food’ diet.”
“We’re not yet sure why not know why some of our data showed significantly greater benefits from diets for women. So more research is needed on this. And we also need to establish how the benefits of a healthy diet are related to improvements in physical health. It could be through reducing obesity, inflammation, or fatigue — all of which are linked to diet and impact upon mental health,” added Dr. Firth.
Another recent UK study, this time from the University of Leeds, also found that increasing fruit and vegetable intake could help boost mental well-being. After looking at data from more than 40,000 participants, the team found that eating just one extra portion of fruits and vegetables a day appeared to have an effect on mental well-being equivalent to completing around eight extra days of walking a month, defined as walking for at least 10 minutes at a time.